Aerosol Radiative Impact on the Middle East Regional Climate and the Red Sea

Handle URI:
http://hdl.handle.net/10754/626143
Title:
Aerosol Radiative Impact on the Middle East Regional Climate and the Red Sea
Authors:
Osipov, Sergey ( 0000-0002-8811-5501 )
Abstract:
The climate in the Middle East is complex and remains poorly understood. Due to the vast Arabian Desert, it is very sensitive to radiative forcing. Mineral dust is the dominant aerosol in this region. High background dust loading and frequent dust outbreaks significantly perturb the radiative balance and contribute to climate variability in the Middle East. To assess the climatological impact of dust in the region, we derived the aerosol optical properties and used a standalone column model to quantify radiative forcing sensitivity to a range of parameters representative of the Arabian Peninsula and the Red Sea. Simulations and modeling assumptions were validated using available in situ observations and satellite retrievals for fair weather and dust storm conditions. We incorporated the optical properties into the regional coupled ocean-atmosphere model and conducted simulations that represent the regional climate. The analysis shows that dust cools the Earth-atmosphere system and thus offsets the warming due to greenhouse gases. Dust reduces the sea surface temperature by 0.4 K, significantly perturbs energy balance, overturning circulation, and its purely dynamical impact reduces biological productivity in the Red Sea. In the real world, dust is present permanently and this does not allow to directly observe the climate response to the dust forcing. Volcanic eruptions produce a transient radiative impact that causes a detectable climate response that could be evaluated from observations and compared with simulations. Large equatorial eruptions are known to significantly perturb the Earth’s climate on the global scale, but their regional impact on the Middle East has not been thoroughly investigated. For example, the 1991 Mount Pinatubo eruption had a profound effect on the MENA and caused extensive coral bleaching in the Gulf of Aqaba. The analysis shows that observed cooling in the Middle East was mostly driven by changes in the atmospheric large-scale circulation, forced by the volcanic aerosol. We found that the Red Sea response was quantitatively and qualitatively different than that of the global ocean. However, similar to the global case, major volcanic eruptions significantly contribute to the regional climate variability and has to be accounted for in trend analyses.
Advisors:
Stenchikov, Georgiy L. ( 0000-0001-9033-4925 )
Committee Member:
Genton, Marc G. ( 0000-0001-6467-2998 ) ; McCabe, Matthew ( 0000-0002-1279-5272 ) ; Toumi, Ralf
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Program:
Applied Mathematics and Computational Science
Issue Date:
Oct-2017
Type:
Dissertation
Appears in Collections:
Dissertations

Full metadata record

DC FieldValue Language
dc.contributor.advisorStenchikov, Georgiy L.en
dc.contributor.authorOsipov, Sergeyen
dc.date.accessioned2017-11-09T14:11:38Z-
dc.date.available2017-11-09T14:11:38Z-
dc.date.issued2017-10-
dc.identifier.urihttp://hdl.handle.net/10754/626143-
dc.description.abstractThe climate in the Middle East is complex and remains poorly understood. Due to the vast Arabian Desert, it is very sensitive to radiative forcing. Mineral dust is the dominant aerosol in this region. High background dust loading and frequent dust outbreaks significantly perturb the radiative balance and contribute to climate variability in the Middle East. To assess the climatological impact of dust in the region, we derived the aerosol optical properties and used a standalone column model to quantify radiative forcing sensitivity to a range of parameters representative of the Arabian Peninsula and the Red Sea. Simulations and modeling assumptions were validated using available in situ observations and satellite retrievals for fair weather and dust storm conditions. We incorporated the optical properties into the regional coupled ocean-atmosphere model and conducted simulations that represent the regional climate. The analysis shows that dust cools the Earth-atmosphere system and thus offsets the warming due to greenhouse gases. Dust reduces the sea surface temperature by 0.4 K, significantly perturbs energy balance, overturning circulation, and its purely dynamical impact reduces biological productivity in the Red Sea. In the real world, dust is present permanently and this does not allow to directly observe the climate response to the dust forcing. Volcanic eruptions produce a transient radiative impact that causes a detectable climate response that could be evaluated from observations and compared with simulations. Large equatorial eruptions are known to significantly perturb the Earth’s climate on the global scale, but their regional impact on the Middle East has not been thoroughly investigated. For example, the 1991 Mount Pinatubo eruption had a profound effect on the MENA and caused extensive coral bleaching in the Gulf of Aqaba. The analysis shows that observed cooling in the Middle East was mostly driven by changes in the atmospheric large-scale circulation, forced by the volcanic aerosol. We found that the Red Sea response was quantitatively and qualitatively different than that of the global ocean. However, similar to the global case, major volcanic eruptions significantly contribute to the regional climate variability and has to be accounted for in trend analyses.en
dc.language.isoenen
dc.rightsThis work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License https://creativecommons.org/licenses/by-sa/4.0/).en
dc.titleAerosol Radiative Impact on the Middle East Regional Climate and the Red Seaen
dc.typeDissertationen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen
dc.contributor.committeememberGenton, Marc G.en
dc.contributor.committeememberMcCabe, Matthewen
dc.contributor.committeememberToumi, Ralfen
thesis.degree.disciplineApplied Mathematics and Computational Scienceen
thesis.degree.nameDoctor of Philosophyen
dc.person.id118390en
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